Revert "🏗 Increase karma browser activity timeout to 5min"

[rcebulko]

Reverts #26887

There's a bigger bug to be fixed; beta browser runs are not being batched. Rolling back until the underlying bug is found

[rsimha]

Force merging to unblock development.

[estherkim]

There's a bigger bug to be fixed; beta browser runs are not being batched. Rolling back until the underlying bug is found

There are only 2 beta browsers. By batching do you mean running them 1 by 1?

[estherkim]

It it helps, #24323 has context on why browserNoActivityTimeout was originally changed from 15 min to 2.

[rsimha]

There's a bigger bug to be fixed; beta browser runs are not being batched.

There are only two beta browsers on which integration tests run. I think the real issue is in running tests in parallel on several stable browsers with a large browserNoActivityTimeout.

As @estherkim said, I don't think this is a bug so much as something that didn't work well with increasing browserNoActivityTimeout. It will help to first understand how all these timeout values interact. I think it's also worth restoring the missing heartbeat functionality and seeing what difference it makes.